Today's ultrasonic parking systems are based on ultrasonic sensors that function in transmission/reception operation and are integrated as distributed systems in the rear and/or front bumpers. In each particular case, four to six such sensors are configured and vertically oriented in the front and rear in a way that allows the individual sound fields to cover the entire space in front of and to the rear of the vehicle. No ground reflections are captured. Systems of this kind have a decisive warning function when an object is detected in the sound space. To improve the functionality of such ultrasound-based systems, more recent applications employ array sensors, which include a matrix or a line of a plurality of ultrasonic sensors.
The European Patent Application EP 0 853 919 A2 discusses a configuration of ultrasonic sensors that encompasses a flexible material including printed conductors. Provided on the flexible material are ultrasonic elements and integrated electronics that are interconnected via signal lines on the flexible material.
The German Patent Application DE 10 2011 077 553 A1 discusses an ultrasound transducer having a piezoelectric ceramic, a printed circuit board and a pot-shaped diaphragm. The piezoelectric ceramic is fastened to a front side of the pot-shaped diaphragm. The piezoelectric ceramic is also connected via at least two lines to signal terminals of the printed circuit board, the signal terminals being provided on a section of the printed circuit board in the interior of the pot-shaped diaphragm. The lines themselves are configured as wires or as single-wire stranded cables.
The German Patent Application DE 10 2009 040 374 A1 discusses an ultrasound transducer having a decoupling ring for attenuating mechanical vibrations that is configured between a shielded, conductive housing and a vibration generating diaphragm. The decoupling ring is made of a conductive material and establishes a conductive connection between the diaphragm and the ground potential.
During manufacture of such sensor systems, the piezoelectric ceramics are contacted using methods such as thermocompression welding. However, they are not easy to replace during assembly of ultrasonic arrays since the contacting must be carried out very precisely and within the smallest possible space. In addition, weak spots can occur in the case of contacts that are produced by thermocompression welding. Such weak spots diminish the quality of the contacting and the service life of such sensors. Therefore, there is continued interest in providing a contacting method for sensors, in particular sound transducers, that makes the contacting of the individual sensor elements simple, reliable and cost-effective.